Fix MATE panel coloring issues

New release with lots of bugfixes from my side project

• Xfce4 panel now looks like it does on Windows 10
• Global look is closer to Windows 10
• Linked widgets get shadows acting as borders to avoid having a "shared" grey border with the side buttons
• Scrollbar now works normally. Extra: added overlay scrollbar as used in Windows 10 settings
• Switches and scale sliders now look as on Windows
• notebook corrections
• code is now auto-generated for GTK3 from the Azurra framework
• added maximized restore button just like on Windows 10

Stable release with full 3.20 compatibility

For an easier installation, this release includes a shell script that installs the theme and makes the necessary changes for your desktop to be like Windows 10

Features

• Now installing latest theme from rolling branch
• Simple installation and removal
• Automatic changes for a better Windows 10 experience